Drugs used in surgery

Question 1

Thiopental sodium?

Answer 1

Barbituate.
Binds to GABAa receptor - enhances GABAergic transmission. Potentiates effects of GABA. More Cl- can pass. Hyperpolarisation. Inhibit CNS transmission.

Induction anaesthesia.

High speed of onset - removed by distribution into fat stores…when these are full the conc in the blood will shoot up!

Question 2

Isoflurane.

Answer 2

General inhalation anaesthetic.
Maintenance.
Act on inhibitor receptors - glycine?
Irratic breathing.
Use with an iv anaesthetic.

Descending depression first - if you get brain stem depression - nearly dead. Therefore give muscle relaxants first.

Question 3

Atracurium.

Answer 3

nACh receptor reversible comp antag.
Non selective cation channel.
Stops reflex contractions of skeletal muscles.
Use with a general anaesthetic.
Must be ventilated - put on an endotracheral tube to relax muscle.

Reduces the amount of anaesthetic needed.

Question 4

Suxamethonium.

Answer 4

Agonist of nAChR.

causes relaxation - act very rapidly.

Question 5

Atropine?

Answer 5

Muscarinic antagonist.
Decreases bronchial secretions.
Dries airways.
Overcome vagal slowing of the heart.

Question 6

Bupivacaine.

Answer 6

LA.
Voltage gated sodium channels in sensory neurones that normally carry pain impulses.
Prevents pain reaching brain.
Given to the spine.
Minimises post op hyperanalgesia.
The more often you use a synapse the stronger it become - LTP. More sensitive to pain after surgery.

Question 7

Morphine

Answer 7

Opioid receptor agonist.

Prevents post surgical hyperalgesia.

Question 8

Fentanyl

Answer 8

Opioid receptor agonist.

Prevents post surgical hyperalgesia.

Question 9

Diazepam

Answer 9

Potentiates the effects of GABAa.
Use pre-op to sedate patients.
BDZ

Question 10

Ibuprofen?

Answer 10

Post op - reduce pain.
Non selective COX inhibitor.
NSAID.
Pain of inflammation.

Question 11

Labetalol.

Answer 11

A and B antagonist.
Lowers BP - minimised bleeding.
lows the heart as sympathetic nervous system with be high as the patient is nervous.

Question 12

Sodium nitroprusside.

Answer 12

Releases NO.
Prodrug.
Soluble Gunaylyl cyclase. PKG. Phosphorylates…. decrease Ca…relaxes SM.

Question 13

Verapamil.

Answer 13

Class 4 antiarrythmia.
L-type Ca++ channel blocker.
Cardiac.

Question 14

Flumazenil.

Answer 14

BDZ receptor antag.
Reverse effects of diazepam.
Post surgery if very drowsy.

Question 15

Neostigmine.

Answer 15

Inhibits AChE
Increase [ACh]
Speeds up recovery from muscle relaxants.